Manafort Brothers – Bridgeport Route 8/25 Bridge Replacement

Manafort Brothers is setting an example for the first design/build highway project in Connecticut and using prefabricated bridge units to do it.

By Russ Gager

Drivers complain about poor highway infrastructure, but they do not like being rerouted when it is being improved. So the Connecticut Department of Transportation (CTDOT) decided to accelerate replacement of four bridges on Route 8/25 in Bridgeport, Conn., by using the accelerated bridge construction (ABC) technique coupled with the design/build project delivery method for the first time and having the general contractor of the project, Manafort Brothers, prefabricate bridge components. This will limit long-term lane restrictions for bridge construction to two two-week periods during the entire project.

Through this pilot program, Manafort Brothers and its team of engineers, and subcontractors are reducing 16 spans of elevated bridges to six. “The project has been an invaluable opportunity for us and all parties involved,” Manafort Brothers Heavy Highway Department Manager Justin Gill maintains.

“Being the pilot design/build for this project has required that our team, including the owner, navigate some uncharted water together in an effort to set the tone for future design/build projects,” Gill continues. “That presents its own set of variables, and we constantly double-back to ensure that we don’t have any oversights. I think so far our design partner, WSP|Parsons Brinckerhoff, CTDOT and Manafort Brothers have done a good job of that.”

Weathering steel beams are being used on the new bridge in place of concrete beams. The two steel beams are fabricated with an integral concrete deck to form a double tee section. Narrow longitudinal closure pours placed after the PBUs are installed connect the PBUs to create a continuous concrete deck. Four prefabricated bridge units (PBUs) are being used per span.

The first of those two-week closures is scheduled for June, during which crews will be working 24/7 to complete their work. The southbound traffic will be redirected to the northbound side of the highway so that both directions of traffic are on one side of the highway.

Then for the second closure in July, the same will be done on the newly constructed side of the highway. At any time during the two-week closures, two lanes of traffic southbound and three northbound will all be on the same side of the highway. CTDOT estimates that without the ABC method, the bridge replacement – which began in June 2015 – would have taken two years and required several stages of construction that would have resulted in reduced vehicle capacity. Instead, it is scheduled for completion in September.

Prefabrication Preparation

Eleven months of prefabrication and preparation has been required by a whole team of Manafort employees and several subcontractors to lead up to that two-week closure.

Eight spans of the previous bridge built in 1973 will be demolished, three cast-in-place retaining walls had to be built, the bridge components prefabricated and 40,000 cubic yards of fill put in place. The fill was required to eliminate 10 of the existing spans on the Lindley St. bridges that are currently seven-spans in both the northbound and southbound direction. The Lindley St. structures will be reduced to two spans and the fill required to do this will be supported by the new retaining walls.

Additionally, an existing 600-foot-long metal bin wall-type retaining wall is being rehabbed with a combination precast and cast-in-place wall. Some of the existing concrete piers had to be rehabbed prior to placement of the PBUs. An existing back wall will be removed and an integral back wall installed in its place.

“Part of the challenge was to develop a design that reflected the amount of work we had to perform in such a condensed time period,” Gill says. “With our design partner, WSP|Parsons Brinkerhoff, we were able to balance a creative design that met the needs of CTDOT, with productive elements that would allow our field personnel to meet the time constraints.”

The First Time

The Route 8/25 bridge replacement is the first design/build project CTDOT has done and one of the few projects where ABC techniques have been chosen. Manafort Brothers was selected for the design/construction contract in a best-value design/build proposal process in which price and technical approach were scored and used to select the proposer that offered the best value.

The award was made to the design/build team with WSP|Parsons Brinckerhoff in May 2015. Manafort and WSP|Parsons Brinckerhoff were brought in at about the 60 percent design stage of the project and tasked with completing the design of the project while commencing construction operations concurrently. “We took CTDOT’s base design and modified it to our approach for the project,” Gill recalls. “Among other things, we modified the size of the PBUs to fit our plan for the rest of the project.”

The PBUs were assembled as a complete bridge structure at a yard along the highway approximately 3,000 feet from the bridges. During the two two-week periods, the completed bridge spans will be disassembled and trucked down local and frontage roads to the bridge location.

Placing the PBU concrete during the late fall and early winter of 2015/2016 was eased by unseasonably warm weather. All the PBU concrete was placed before the first snow of the season. Some heating of the concrete still was required, but less than would have been required in a typical Connecticut winter.

The Route 8/25 bridge replacement project requires the contractor to have a robust quality control program and a full staff of quality control professionals including a quality control administration, a quality control manager for construction and a quality control manager for design. Manafort Brothers is responsible for the design component of the project and also key elements of the project that the company chose to self-perform, including construction of the PBUs, retaining walls, earthwork and demolition of the existing structures.

Gill attributes the success of the project “to the talented and dedicated professionals that we have involved from Manafort Brothers and WSP|Parsons Brinckerhoff. Our experienced construction professionals combined with the engineering expertise that WSP|Parsons Brinckerhoff brings to the table has made for a great team. Manafort’s diversity and the involvement of our highway, demolition and structural concrete divisions allows us the ability to self-perform the key components of the project.”